JP2011138853A - Connection structure of flexible printed circuit and optical pickup device - Google Patents

Abstract

【Task】
Provided is a structure in which connection strength of a connection portion is improved in connection between a first flexible substrate fixed to a main body of a thin optical pickup device and a second flexible substrate inserted into a connector of a drive.
[Solution]
In the connection structure of the flexible substrate in which the first flexible substrate and the flexible substrate are connected, a through hole is provided in the second flexible substrate, and the resin member penetrates the through hole and wiring on the connection surface of the first flexible substrate By adhering to the surface opposite to the connection surface of the second flexible board, the impact is absorbed by the elasticity of the resin, and the metal of the wiring layer has strong adhesive strength for the first flexible board. Bonding is performed and the second flexible substrate is bonded to the back surface side where no peeling stress is applied, thereby improving the connection strength against peeling.
[Selection] Figure 1

Description

  The present invention relates to an optical pickup device used for reproducing and recording an optical disc such as a CD (compact disc) and a DVD (digital versatile disc), and a flexible substrate connection structure used for the optical pickup device.

  Conventionally, a thin optical pickup device (thickness: 7 mm or less) used for reproducing and recording an optical disk such as a CD or DVD, or an optical disk drive device incorporating a thin optical pickup device has a structure as shown in FIG. ing. Light-emitting elements, various lenses, and mirrors, which are components for configuring the optical system in the case 3 for optical pickups composed of die-casting and molding mainly composed of metals such as Zn, Mg, and Al and PPS (poly phenylene sulfide) resin A light receiving element (not shown) and the like are arranged, and the flexible substrate 2 is used as a means for supplying an electric signal or the like. This flexible board 2 has a structure in which the flexible board 2 is integrated up to the portion 8 to be inserted into the connector on the drive side, because the optical disk drive becomes thinner and the height can not be used. .

  FIG. 10 shows a state in which the optical pickup device is incorporated in the optical disk drive device. The optical pickup device body 1 moves between the outer periphery and the inner periphery with the objective lens 5 facing the upper surface side, further facing the optical disk (not shown) on the upper surface side through the notch portion of the drive side cover 9. While reading and writing information. A state in which these components are incorporated in the optical disc drive main body 10 is a product.

  As described above, the flexible substrate used in the thin optical pickup has a structure that is mainly integrated. However, the originally required performance differs depending on the portion arranged on the inside and outside of the pickup. Emphasis on high density and flexibility on the outside. Therefore, in the integrated flexible board 2, as a method to satisfy both the required performance of the part fixed to the optical pickup device body and the part inserted into the connector on the drive side, it is optimal for both high density and flexibility It has been cited as a solution to select and connect a flexible substrate having a good performance.

  In addition, in a small optical pickup device, various components must be arranged in high density and in the horizontal and vertical directions, so the flexible board that handles these signal transmissions must have a complicated shape. . This makes it impossible to increase the number of required shapes to be extracted from one original sheet, and the required processing differs depending on the part, so even the part that requires a simple configuration is the most troublesome part. In some respects, the flexible substrate was required to be divided from the viewpoint of cost.

Further, an optical pickup device as shown in FIG. 8 or an optical disk drive device incorporating a thin optical pickup device is assembled through a plurality of complicated processes. Therefore, after the adjustment process of the light-emitting element, light-receiving element and various optical components of the optical pickup device is performed, there are many dents, scratches, etc. generated in the assembly process on the outer flexible substrate, often resulting in defective products. By introducing flexible substrate division / connection, it is possible to improve product yield and reduce costs. (For example, see Patent Documents 1 and 2)
Because of the limitation of the thickness of the optical pickup, the connector as in Patent Document 3 cannot be used to connect the two flexible boards, and they are connected by solder. As shown in Fig. 9 (a), when introducing the division / connection of a flexible substrate, the conductor pattern of the first flexible substrate and the conductor pattern of the second flexible substrate are opposed to each other, and the second flexible substrate The board becomes the back surface, and the connector side contact 8 is reversed. Therefore, as shown in FIG. 9 (b), the other end of the first flexible substrate and the other end of the second flexible substrate are connected together so that they overlap, and the connection end of the flexible substrate is connected to the optical pickup device. If the connection end of the first flexible board is fixed 90 degrees in the height direction (vertical direction) and the connection end of the second flexible board is bent 180 degrees, the connector-side contact 8 is directed upward.

JP 2005-276263 A JP 2006-245514 A Japanese Unexamined Patent Publication No. 2006-310449

  However, in the case of the connection structure shown in Fig. 9 (b), the connecting portions of the first and second flexible boards are likely to be stressed in the peeling direction, and the flexible boards face each other as shown in Fig. 9 (a). When compared with the average shear strength of 3kgf of the connection part 2-c when combined, the peel strength of the connection part 2-d in the connection structure of Fig. 9 (b) is 1.5kgf or less on average, which significantly reduces the connection strength. Tend to.

  Further, in the portion where the flexible substrate is pulled out from the cover 4 from the optical pickup device where the split connection can be introduced in the flexible substrate, many places where the wiring is narrow are arranged, the portion where the wiring width such as the ground line is wide and the signal line A portion with a narrow wiring width is mixed, but a wiring with a narrow wiring width tends to be on one side. For this reason, a wiring with a narrow wiring pattern width of 100 μm or less is often used as the outermost wiring, and when a flexible substrate divided connection is introduced, from the end of the conductor pattern of the outermost conductor pattern of the connecting portion with a narrow wiring width. The structure is easy to peel.

  From the above, in order to introduce the division / connection of the flexible substrate, a structure capable of easily performing the reinforcing connection to the connection portion is required.

  An object of the present invention is to provide a structure in which reinforcing connection to a connection portion can be easily performed in connection between divided and solder-connected flexible boards.

  In order to solve the above problems, the present invention provides a connection structure of a flexible substrate in which the first flexible substrate and the flexible substrate are connected, wherein the first flexible substrate is provided with a through hole, and the resin member is a through hole. The connection surface of the second flexible substrate and the surface opposite to the connection surface of the first flexible substrate are bonded to each other.

  As described above, with the structure according to the present invention, it is possible to improve reliability and durability at the connection portion between the flexible substrates in the optical pickup.

FIG. 3 is a cross-sectional view of a connection portion between a first flexible substrate and a second flexible substrate according to an embodiment of the present invention. FIG. 3 is a cross-sectional view of a first flexible substrate and a second flexible substrate according to an embodiment of the present invention. FIG. 3 is a top view of the connection portion of the first flexible substrate according to one embodiment of the present invention. FIG. 6 is a top view of a connection portion of a second flexible substrate according to an embodiment of the present invention. FIG. 6 is a top view of a protrusion of a second flexible substrate according to an embodiment of the present invention. FIG. 6 is a perspective view showing a state in which the first flexible substrate and the second flexible substrate according to an embodiment of the present invention are divided at the ends in the traveling direction of the optical pickup case. FIG. 6 is a perspective view showing a state where the divided first flexible substrate and the second flexible substrate are connected at the end portion in the traveling direction of the optical pickup case according to an embodiment of the present invention. It is a perspective view which shows the state which attached the metal cover to the optical pick-up apparatus of FIG. It is a perspective view of the thin optical pick-up apparatus concerning a prior art example. FIG. 10 is a cross-sectional view of a connection portion between a first flexible substrate and a second flexible substrate according to a conventional example. FIG. 3 is a cross-sectional view of a connection portion between a first flexible substrate and a second flexible substrate according to an embodiment of the present invention. It is a perspective view of the state where a thin optical pick-up device was built in an optical disk drive device. FIG. 6 is a top view of the connection portion of the first flexible substrate according to another embodiment of the present invention. FIG. 6 is a top view of a connection portion of a second flexible substrate according to another embodiment of the present invention. FIG. 6 is a top view of the connection portion of the first flexible substrate according to another embodiment of the present invention. FIG. 6 is a top view of a connection portion of a second flexible substrate according to another embodiment of the present invention. FIG. 6 is a top view of the connection portion of the first flexible substrate according to another embodiment of the present invention. FIG. 6 is a top view of a connection portion of a second flexible substrate according to another embodiment of the present invention. FIG. 6 is a top view of the connection portion of the first flexible substrate according to another embodiment of the present invention. FIG. 6 is a top view of a connection portion of a second flexible substrate according to another embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. The optical pickup device 1 is an optical pickup composed of various optical components including an objective lens 5, a light emitting element, a light module of a light receiving element, a die casting or a mold mainly composed of one of metals, such as Zn, Al, Mg, and PPS, and a resin. Case 3, a first flexible substrate 2-a fixed to the optical pickup device body on which a chip component is mounted on the optical pickup case 3, a second flexible substrate 2-b inserted into the connector on the drive side, and The cover 4 is finally limited in height, and the flexible substrates 2-a and 2-b are generally made of a resin containing polyimide or an adhesive and a metal containing copper foil. The technology for connecting divided flexible substrates according to the present invention is mainly applied to a thin optical pickup device, but can also be applied to a product that connects other flexible substrates.

  First, in order to describe the embodiment of the present invention, the mutual positional relationship of each component in the optical pickup device will be described with reference to FIGS. 5, FIG. 6, and FIG. 7 are perspective views of a first flexible substrate fixed to the optical pickup device main body on the optical pickup device and a second flexible substrate connection inserted into the drive-side connector.

  FIG. 5 is a perspective view showing a state in which the first flexible substrate and the second flexible substrate are divided at the end portions in the traveling direction of the optical pickup case 3. FIG. As shown in FIG. 5, the first flexible substrate 2-a fixed to the optical pickup device main body is mounted on the objective lens 5 side on the optical pickup case 3. The traveling direction indicates that a part of the optical pickup case 3 engages with the main shaft side shaft 6 and the sub shaft side shaft 7 and reciprocates in the axial direction of the shaft.

  In the first flexible substrate 2-a fixed to the optical pickup device main body, the state after testing is performed, that is, the state after the adjustment process of the light emitting element, the light receiving element and various optical components of the optical pickup apparatus is performed. Show. As a testing method, a probe pin or a connector may be used.

  FIG. 6 is a perspective view showing a state in which the divided first flexible 2-a substrate and second flexible substrate 2-b are connected at the end of the optical pickup case 3 in the traveling direction. As shown in FIG. 6, the second flexible board 2-b inserted into the connector on the drive side is aligned with the first flexible board 2-a fixed to the optical pickup device body, and then The flexible substrates 2-a and 2-b are connected to each other by pressurizing and heating the connecting portion with a heating head (not shown).

  FIG. 7 is a perspective view showing a state in which a metal cover 4 is attached to the optical pickup device so that the connected flexible boards 2-a and 2-b shown in FIG. 6 do not warp.

  Next, an embodiment of the present invention will be described in detail with reference to a cross-sectional view and a top view of the connecting portion shown in FIGS.

  3A is a top view of the connecting portion of the first flexible board 2-a according to the present embodiment, and FIG. 3B is a second flexible board 2-inserted into the connector on the drive side. It is a connection part top view of b. FIG. 2 is a cross-sectional view taken along line AA in FIGS. 3A and 3B in a state where the first flexible substrate 2-a and the second flexible substrate 2-b are overlapped.

  In the configuration of the first flexible substrate 2-a shown in FIG. 2, a conductor pattern (wiring copper foil) 2-a1 is applied to the base film 2-a3 through an adhesive (not shown). . A cover film 2-a2 is attached with an adhesive (not shown) so as to cover the surface of the conductor pattern 2-a1. Further, the portion of the conductor pattern 2-a1 where the cover film 2-a2 is not provided is used for mounting a semiconductor chip component or connecting to the second flexible substrate 2-b. This portion is provided with solder plating 2-a4 in order to facilitate connection with a component or a mating substrate. The plating thickness is preferably 5 μm to 15 μm because a solder fillet is formed at the time of connection.

  FIG. 2 also shows the connection portion side end 2-b6 of the second flexible board 2-b inserted into the connector on the drive side with respect to the connection portion side end 2-a6 of the first flexible board 2-a. The position is shown. The configuration of the second flexible substrate 2-b is similar to that of the first flexible substrate 2-a, in which the conductor pattern 2-b1 is applied to the base film 2-b3 via an adhesive. A cover film 2-a2 is attached with an adhesive so as to cover the surface of the conductor pattern 2-b1. In the conductor pattern 2-b1, a portion without the cover film 2-a2 is used for connection with the first flexible substrate 2-a. In this portion, in order to facilitate connection with the counterpart substrate, metal plating 2-b4 by nickel plating and gold plating is applied on the conductor pattern 2-a1. For the metal plating 2-b4, solder plating or a combination of different kinds is selected and applied to the surface depending on the performance required during and after connection.

  As shown in FIGS. 3A and 3B, connection portions 2-a8 and 2-b8 are formed on the first flexible board 2-a and the second flexible board 2-b, respectively. Yes. In the connection portion, the cover film is not formed on the conductor patterns 2-a1 and 2-b1, but the cover film is formed in portions other than the conductor pattern. In the drawing, for the sake of convenience, the boundaries between the connecting portions 2-a8, 2-b8 and other portions are indicated by solid lines. The first flexible substrate 2-a is on the outer side of the outermost conductor pattern of the connection portion conductor pattern 2-a4 and is farthest from the end portion 2-b6 of the flexible substrate of the connection portion 2-a8. The through hole 2-a7 is formed at the position where the connection portion conductor pattern 2-b4 of the second flexible substrate is outside the outermost conductor pattern, and the end portion 2-b of the connection portion 2-b8. A conductor pattern projection 2-b7 is formed at a position farthest from b6. When the two flexible substrates 2-a and 2-b are overlapped, the through hole 2-a7 and the protruding portion 2-b7 are overlapped.

  FIG. 1 is a cross-sectional view of a connecting portion including a reinforcing portion cut in parallel with 2-a6 after connecting the first flexible substrate 2-a and the second flexible substrate 2-b inserted into the connector on the drive side. 3 and corresponds to the cross section of the portion BB in FIGS. The first flexible substrate and the second flexible substrate have their conductor patterns 2-a1 and 2-b1 facing each other and connected by solder 2-a4, and through the through hole 2-a7, the protruding portion 2 is connected. -b7 and the base film 2-a3 of the first flexible substrate are bonded by a reinforcing material 2-e which is a resin member. Here, the reinforcing material 2-e may be adhered only to the base film 2-a3 side, but it is more preferable that the through hole is filled with the reinforcing material and is also adhered to the cover film 2-a2 side. .

  There is no problem as long as the reinforcing material 2-e has high adhesion to the polyimide, which is the material of the flexible substrate, and the conductor of the protruding portion. For example, rubber-based, cyanoacrylate-based, polyurethane, silicone, modified silicone, acrylic-based, and epoxy-based ultraviolet curable adhesives, thermosetting adhesives, and the like are desirable.

  Here, the effect | action of the connection structure of this invention is demonstrated. When the main connection portion 2-a8 of the first flexible substrate and the main connection portion 2-b8 of the second flexible substrate are connected, the connection shown in FIG. 9B is obtained. When stress is applied so that the second flexible substrate 2-b is pulled, the stress is applied in the direction in which the connection portion 2-d is peeled off. At this time, the length direction of the conductor pattern of the flexible substrate is the largest on the side (the lower side in FIGS. 3A and 3B) where the connector portion (device connection portion) is provided among the connection portions. In the width direction, a large stress is likely to be applied to the outermost conductor pattern on either the left or right side of the drawing, and peeling is likely to start in the stressed portion. Further, when the peeling starts and a crack occurs in the solder, the crack expands and the peeling easily proceeds. That is, a large stress is applied to the portion where the through hole 2-a7 and the protruding portion 2-b7 are provided, and peeling is likely to occur from here.

  In this embodiment, the through hole 2-a7 and the protruding portion 2-b7 are provided on the side immediately outside the outermost conductor pattern portion where the stress is most likely to be applied to the connection portion, and closer to the device connection portion at the connection portion. The peel strength can be improved by providing and adhering the outside of the solder connection portion between the first flexible substrate and the second flexible substrate with a reinforcing material. Since the reinforcing material 2-e is made of resin, its elastic modulus is lower than that of the outermost conductor pattern connecting portion formed by the hitting solder 2-a4, and has an effect of relaxing the stress applied to the connecting portion.

  Here, it is desirable that the reinforcing material has a high adhesive force to the metal constituting the conductor pattern 2-b4, the cover film 2-a2, and the base 2-a3. In general, the adhesive made of resin constituting the reinforcing material has a higher adhesive force to the metal constituting the conductor pattern than to the resin constituting the base film or the cover film. Therefore, if a metal layer is provided on the base 2-b3 and the reinforcing material 2-e is bonded to the metal layer, the adhesive force of the reinforcing material 2-e to the second flexible substrate 2-b can be increased. . In addition, if this metal layer is made of the same material and the same layer as the conductor pattern 2-b4, it can be formed together in the process of forming the conductor pattern 2-b4 on the base film 2-b. . Further, if the protrusion 2-b7 is formed integrally with the conductor pattern, it is possible to suppress the protrusion 2-b7 from being peeled off from the base film 2-b3 due to peeling stress.

  In addition, since the protrusions 2-b7 and the through holes 2-a7 are immediately adjacent to the conductor pattern, the reinforcing material is also bonded to a metal such as the conductor pattern 2-a1 and the solder 2-a4 of the first flexible substrate. , Adhesion is improved.

  Further, if the positions of the protrusions 2-b7 and the through holes 2-a7 in the longitudinal direction of the flexible substrate are set to be closer to the device connection part (rather than half), the reinforcing part 2-e can easily receive the stress applied to the connection part. . Here, the protruding portion 2-a7 becomes a device connecting portion rather than the solder connecting portion at the connecting portion, or the device connecting portion side so that a part of the protruding portion 2-b7 on the device connecting portion side is covered with the cover film. It may be arranged close to.

  On the other hand, on the first flexible 2-a side, the reinforcing material 2-e is directly bonded to the base film 2-a3 on the side opposite to the cover film 2-a5 through the through hole 2-a7. If a metal layer is also provided on this bonded portion, the adhesive strength is increased. However, since the number of steps is increased only for providing the metal layer on the surface having no conductor pattern, the manufacturing cost increases. However, the direction of adhesion between the reinforcing material 2-e and the base film 2-a3 is opposite to the direction in which the peeling stress of the connecting portion is applied. Since it works in the direction of pressing, no problem arises even if the adhesive force is relatively weak.

  As described above, since the base film 2-a3 and the base film 2-b3 are bonded with the reinforcing material, the outermost conductor pattern is also prevented from being peeled off from the base film 2-a3 due to peeling stress.

  FIG. 4 is an enlarged top view of the protruding portion 2-b7 of the second flexible substrate.

  A signal line having a conductor pattern width narrower than that of a power supply line or the like tends to be arranged on one side of the flexible substrate, and a conductor pattern having a conductor pattern width of 100 μm or less may be arranged on the outermost side. In order to sufficiently improve the mechanical strength of the connecting portion, the protrusion width C (including the conductor pattern) of the protrusion 2-a7 of the second flexible substrate is preferably C> 100 μm. Similarly, the protrusion length D of the protrusion 2-a7 is preferably D> 100 μm. Further, it is desirable that the through hole 2-a7 has the same size.

  As described above, if the structure in the present invention is taken, the outermost conductor pattern connection portion is reinforced with a reinforcing material in the connection when connecting the flexible substrates in the optical pickup, and is strong against tension and bending. Reliability and durability can be improved.

  The connection method of the 1st and 2nd flexible substrate concerning a present Example is demonstrated. Connection is performed in the order of solder joint and reinforcement material preparation.

  First, the first flexible board 2-a and the second flexible board 2-b are placed on a positioning jig, and the connection portions 2-a8, 2-b8 (especially conductor pattern 2- Align so that a1, 2-b1) overlap. Then, by applying a heating head and heating and melting the solder 2-a4, the conductor pattern 2-a1 and the conductor pattern 2-b1 are solder-joined.

  At this time, conventionally, when the conductor pattern of the second flexible board 2-b inserted into the connector on the drive side is overlaid on the first flexible board 2-a, there is a problem that the positioning is difficult. there were. In the present embodiment, the through holes 2-a7 and the protrusions 2-b7 are provided, and these positions may be aligned, so that the flexible substrates can be easily aligned.

  Further, conventionally, when the second flexible board 2-b to be inserted into the drive-side connector is positioned with respect to the first flexible board 2-a and heated and melted, a heating head is formed from the back surface of the flexible board. Therefore, it is difficult to determine the boundary between the conductor pattern and the coverlay, and it is difficult to align the heating head. In the present embodiment, by providing the through hole 2-a7 and the protruding portion 2-b7, an easy-to-see alignment target can be formed, and the heating head can be easily aligned.

  After soldering the conductor patterns of both the flexible boards 2-a and 2-b, the reinforcing material 2-e attaches the adhesive that becomes the reinforcing material 2-e through the through-hole 2-a7 between the flexible boards and It is manufactured by supplying and curing on the first flexible substrate. The adhesive must be supplied after the solder is heated and melted. However, since the adhesive can be supplied between the flexible substrates through the through holes after joining the flexible substrates, the supply of the adhesive is easy.

  FIG. 11A is a top view of the connecting portion of the first flexible board 2-a according to the second embodiment. FIG. 11B is a second flexible board 2-inserted into the connector on the drive side. It is a connection part top view of b. In the present embodiment, the through hole 2-a7 of the first flexible substrate and the projection portion 2-b7 of the second flexible substrate are provided on the device connecting portion side from the half of the connecting portion in the longitudinal direction of the flexible substrate connecting portion. ing. Other points are the same as in the first embodiment.

  As in this example, even when the through hole 2-a7 and the projection 2-b7 are not arranged on the device connection part side of the connection part, the reinforcing material 2-e sufficiently exhibits its function and is flexible. Contributes to improving the reliability and durability of the board connection.

  12A is a top view of the connecting portion of the first flexible board 2-a according to the third embodiment, and FIG. 12B is a second flexible board 2-inserted into the connector on the drive side. It is a connection part top view of b. In the present embodiment, a plurality of through-holes 2-a7 of the first flexible substrate and protrusions 2-b7 of the second flexible substrate are arranged in the longitudinal direction of the flexible substrate. Other points are the same as in the first embodiment.

  If the reinforcing material 2-e is increased, the reliability and durability of the connecting portion are further improved. As in the embodiment, a plurality of through-holes 2a-7 and protrusions 2-b7 may be arranged on one side instead of one on each side with respect to the plurality of conductor pattern groups. Connection strength is improved.

  The positions where the through holes 2-a7 and the protrusions 2-b7 are provided are not limited to the positions as in the present embodiment, and may be provided in a form in which the conductor patterns are not short-circuited between a plurality of conductor patterns, for example. . Further, if the through hole 2-a7 does not electrically isolate the conductor pattern of the first flexible substrate, the reinforcing material is bonded on the conductor pattern without providing a protrusion on the conductor pattern of the second flexible substrate. You may do it.

  FIG. 13A is a top view of the connecting portion of the first flexible board 2-a according to the fourth embodiment, and FIG. 13B is a second flexible board 2-inserted into the connector on the drive side. It is a connection part top view of b. In this embodiment, the first flexible board also has a protrusion 2-a9 having a wiring width larger than that of the other part, and the protrusion 2-a9 has a through hole 2-a7 on the device connection part side. is doing. The protrusion 2b-7 of the second flexible substrate is joined to the protrusion 2-a9 by solder in the same manner as the conductor pattern, and is connected to the through hole 2-a7 by a reinforcing member 2-e. Other points are the same as in the first embodiment.

  According to the present embodiment, in addition to the effect of improving the strength of the connecting portion of the reinforcing member 2-e by the through hole 2-a7 and the reinforcing member 2-e, the protrusion 2b-7 and the protrusion 2-a9 Also, the effect of improving the joint strength by soldering of the connecting portion can be obtained.

  FIG. 14A is a top view of the connecting portion of the first flexible board 2-a according to the fifth embodiment, and FIG. 14B is a second flexible board 2-inserted into the connector on the drive side. It is a connection part top view of b. In the present embodiment, the first flexible substrate and the second flexible substrate each have a through hole and a protrusion, and the first flexible substrate through hole 2-a7 and the second flexible substrate when overlapped with each other. The protruding portion 2-b7 of the substrate overlaps, and the protruding portion 2-a9 of the first flexible substrate and the through hole 2-b9 of the second flexible substrate overlap. Reinforcing material 2-e is formed in the portion where the through hole and the protrusion overlap, as in the embodiment. Other points are the same as in the first embodiment. Also by this, the same effect as Example 1 can be acquired. Further, in the present embodiment, the form of the connecting portion can be the same between the first and second flexible substrates.

  As mentioned above, although Example 1-Example 5 were demonstrated, in any Example, as for the shape of the projection part installed on the connection part outermost conductor pattern of a flexible substrate, the other end of a conductor pattern is 100 micrometers or more. A triangular shape, a sector shape, a trapezoid shape, or the like may be used as long as the structure is such that

  Currently, there are demands for higher performance, such as thinness and performance that can be played back and recorded not only on CDs but also on DVDs that comply with various standards, as required for optical pickup devices. Furthermore, in the future, in order to play back and record next-generation discs, a three-wavelength compatible thin optical pickup device incorporating a blue semiconductor laser will be required.

  For this reason, the flexible substrate used in the optical pickup device is required to have a higher density, has a multilayer structure, and costs are expected to increase significantly. One solution is to divide and connect the integrated flexible substrates. At this time, it is necessary to fix and protect the connecting portions. The present invention is a technique related to the connection of flexible substrates, and can improve yield and reduce costs.

  DESCRIPTION OF SYMBOLS 1 ... Optical pick-up apparatus main body, 2 ... Flexible substrate, 2-a ... 1st flexible substrate, 2-a1 ... Conductor pattern, 2-a2 ... Cover film (polyimide) + adhesion Agent, 2-a3 ... base film (polyimide) + adhesive, 2-a4 ... solder plating, 2-a6 ... other end of flexible substrate, 2-a7 ... through hole on flexible substrate , 2-a8 ... connection part, 2-a9 ... projection, 2-b ... second flexible substrate, 2-b1 ... conductor pattern, 2-b2 ... cover film (polyimide) ) + Adhesive, 2-b3 ... Base film (Polyimide) + Adhesive, 2-b4 ... Gold, Nickel plating, 2-b6 ... Other end of flexible substrate, 2-b7 ... Flexible Outer conductor pattern protrusion on substrate, 2-b8 ... connection, 2-b9 ... through hole, 2-e ... reinforcement, 3 ... optical pickup case, 4 ... Objective lens side upper cover, 5 ... Objective lens, 6 ... Main shaft side shaft, 7 ... Sub shaft side shaft, 8 ... Connector insertion part, 9 ... Drive side cover, 10: Optical disc drive main unit.

Claims (14)

First and second flexible substrates each having a resin base, a plurality of metal wirings arranged side by side on the base, and a resin cover covering the opposite side of the wiring from the base; ,
A plurality of wirings of the first flexible substrate and a plurality of wirings of the second flexible substrate are connected to each other at a portion not covered by the cover; and
In the flexible substrate connection structure with
The first flexible substrate and the second flexible substrate each have a first surface to which the flexible substrates are connected, and a second surface opposite to the first surface,
The first flexible substrate has a through hole,
Connection of flexible substrate characterized in that a resin member penetrates the through hole and is adhered to the first surface of the second flexible substrate and the second surface of the first flexible substrate. Construction. In claim 1,
The flexible substrate connection structure, wherein the resin member is bonded to the base on the second surface of the first flexible substrate. In claim 1 or claim 2,
The second flexible substrate has a metal layer on the first surface side of the base;
A flexible substrate connection structure, wherein the resin member is bonded to the metal layer. In claim 3,
The flexible substrate connection structure, wherein the metal layer is formed on both sides of a region where the plurality of wirings are formed side by side. In claim 3 or claim 4,
The wiring structure and the metal layer are formed of the same material in the same layer, and the connection structure of the flexible substrate. In claim 5,
The connection structure of a flexible substrate, wherein the wiring and the metal layer are integrally formed. In any one of Claims 1 thru | or 6.
The wiring of the first flexible substrate and the wiring of the second flexible substrate are connected by solder,
The method for connecting a flexible substrate, wherein the resin member is bonded to the solder or the wiring of the second flexible substrate. In any one of Claims 1 thru | or 7,
The first flexible substrate and the second flexible substrate each have a device connection part connected to another device,
The flexible substrate connection structure, wherein the device connection portion of the first flexible substrate and the device connection portion of the second flexible substrate are on the same side in the longitudinal direction of the flexible substrate with respect to the connection portion. . In claim 8,
In the longitudinal direction of the flexible substrate, the metal layer or the through-hole is provided closer to the device connection portion than a half of the connection portion. In any one of Claims 1 thru | or 9,
A flexible substrate connection structure comprising a plurality of the through holes or the metal layers arranged in the longitudinal direction of the flexible substrate. In claim 8,
The wiring of the first flexible substrate and the wiring of the second flexible substrate each have a wide portion in which the width of the wiring is thicker than other portions,
The wide portion of the second flexible substrate is connected to the wide portion of the first flexible substrate by solder, and is bonded to the resin member at a portion closer to the device connection portion than the connected portion. A flexible substrate connection structure characterized by comprising: The connection structure of the flexible substrate according to any one of claims 1 to 11,
An optical pickup case,
A lens, a mirror, a light emitting element, and a light receiving element;
One of said 1st flexible substrate or said 2nd flexible substrate, and said connection part are arrange | positioned in the said pickup case, The optical pick-up apparatus characterized by the above-mentioned. First and second flexible substrates each having a resin base, a plurality of metal wirings arranged side by side on the base, and a resin cover covering the opposite side of the wiring from the base; ,
A plurality of wirings of the first flexible substrate and a plurality of wirings of the second flexible substrate are connected to each other at a portion not covered by the cover; and
In the manufacturing method of the connection structure of the flexible substrate comprising:
The first flexible substrate includes a through hole,
Connecting the wiring of the second flexible substrate to the first flexible substrate by solder;
After the solder connection, supplying a resin member through the penetrating term, and bonding the first flexible substrate and the second flexible substrate;
The manufacturing method of the connection structure of the flexible substrate characterized by including. In claim 13,
The first flexible substrate and the second flexible substrate each have a first surface to which the flexible substrates are connected, and a second surface opposite to the first surface,
The flexible substrate connection structure, wherein the resin member penetrates the through hole and adheres to the first surface of the second flexible substrate and the second surface of the first flexible substrate. Manufacturing method.

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